Process and agents for the clear rinse in mechanical dishwashing

ABSTRACT

Process for rinsing of dishes in dishwashing machines having one or several clear-rinsing cycles using an aqueous solution of an adduct of from 3 to 30 mols of ethylene oxide to alkanediols with a linear alkane chain of from 10 to 20 carbon atoms and having vicinal, non-terminal hydroxyls, as well as clear-rinsing agents for use in the process.

United States Patent [191 Alrenschopfer er a1.

[ 1 Dec. 18, 1.973

' [22] Filed:

[ PROCESS AND AGENTS FUR Til-11E CLEAR RlNSE IN MECHANICAL DTSHWASHING Inventors: Theodor Mtenschopier,

Dusseldorf-Holthausen; Heimold Bafrlra, Dusseldorf-Reisholz; Giimer Jakolbi, Hilden; Peter Krings, Krefeld; Hans-Jiirgen Lehmann, Mettmann, all of Germany [73] Assignee: Henkel & Cie Gmblll, Dusseldorf,

Germany Dec. 7, 1971 [21] Appl. No.: 205,723

[30] Foreign Application Priority Data Dec. 18, 1970 Germany 2062464 [52] US. Cl 252/142, 252/351, 252/143, 252/162, 252/175, 252/D1G. 1

[51] Int. Cl. ..Cl11d 7/08, C23g 1/02, BOlf 17/00 [58] Field of Search 252/142, 156, 162, 252/175, 327, 351, 321, 358

[56] References Cited UNITED STATES PATENTS 1,970,578 8/1934 Schoeller et al7 252/D1G. 1 3.086944 3/1963 Weddell 252/321 3,284,352 11/1966 Burdyn et a1. 252/321 Primary Examiner.lohn D. Welsh Att0rney-Nelson Llttell et al.

[57] ABSTRACT 10 Claims, N0 Drawings PROCESS AND AGENTS FOR THE CLEAR RINSE IN MECHANICAL DISHWASI'IING TI-IE PRIOR ART In mechanical dishwashing generally two cleaning cycles, usually separated by intermediate rinsing cycles with pure water are used. In the two cleaning cycles, different products are utilized. In the first or true cleaning cycle, alkaline-reacting agents are employed for the loosening and emulsifying of the food residues. In the after-rinsing or clear-rinsing bath, on the other hand, special clear-rinsing agents are employed. The latter should possess a good wetting power and be able to reduce the surface tension of the after-rinsing water to such a degree that it drains in a film-like manner from the dishes and leaves no visible deposits, such as lime spots or other impurities.

Because of the violent agitation of the liquor in the dishwasher, these clear-rinsing agents have to be as low-foaming as possible. It is, however, known that the customary anionic wetting agents, such as highermolecular-weight alkyl sulfates or alkyl sulfonates or aralkyl sulfonates foam too much. In practice, therefore, mostly nonionic tensides based on ethylene-oxide adducts to fatty alcohols, alkylphenols, or polypropylene glycols of higher molecular weights are employed. These products, however, are not sufficiently lowfoaming in the concentration range, required for a sufficient wetting effect, and disturbances in the rinsing process may occur, because of a too strong foam formation in the dishwasher.

Is is furthermore desirable to employ in this process such wetting agents that possess a good biological degradability and low toxicity toward the organisms living in water and thus do not exhibit an undesirable burden on the disposal of the sewage.

OBJECTS OF THE INVENTION An object of the invention is the development of lowfoaming and biologically'degradable clear-rinsing agents for mechanical dishwashing with a good wetting and draining effect toward hard surfaces.

Another object of the invention is the development in the process for the mechanical washing of dishes which comprises subjecting dirty dishes to the action of a washing solution, subjecting the washed dishes to at least one clear-rinsing solution and recovering said washed dishes, the improvement consisting of utilizing an aqueous solution containing from 0.05 to 1.0 gm per liter of an adduct of from 3 to 30 mols of ethylene oxide to an alkanediol having a linear alkane chain with from 10 to 20 carbon atoms and vicinal, non-terminal hydroxyls, as said at least one clear-rinsing solution.

A further object of the present invention is the development of low-foaming rinsing compositions adapted for dishwashers consisting essentially of (A) an adduct of from 5 to 20 mols of ethylene oxide to an alkanediol having a linear alkane chain with from to carbon atoms and vicinal, non-terminal hydroxyls, and (B) an alkoxylated foam suppressing compound selected from the group consisting of (l an alcohol having from 10 to 20 carbon atoms selected from the group consisting of alkanols and alkenols adducted with l to 3 mols of ethylene oxide, (2) alkylphenols having 6 to 12 carbon atoms in the alkyl adducted with l to 6 mols of ethylene oxide, (3) an alcohol selected from the group consisting of alkanols and alkanediols having from l0 to 20 carbon atoms, and alkylphenols having from 6 to carbon atoms in the alkyl, adducted with from 1 to 20 mols of ethylene oxide and from 1 to 20 mols of an alkylene oxide selected from the group consisting of propylene oxide and butylene oxide wherein at least 30 mol percent of said total amount of ethylene oxide and alkylene oxide is said alkylene oxide, (4) formaldehyde acetal adducts of an alcohol selected from the group consisting of alkanols and alkanediols having from 10 to 20 carbon atoms and alkylphenols having from 6 to 12 carbon atoms in the alkyl adducted with from 10 to 30 mols of ethylene oxide, and (5) mixtures thereof, wherein the weight ratio between component A and component B is from 120.2 to 1:4.

These and other objects of the invention will become more apparent as the description thereof proceeds.

DESCRIPTION OF THE INVENTION The objects of the invention have been achieved by the development of clear-rinsing agents for automatic dishwashing based on nonionic, low-foaming tensides that combine the desirable properties to a high degree. The clear-rinsing agents are characterized by a content of adducts of 3 to 30 mols of ethylene oxide to alkanediols with linear alkane chains of from l0 to 20 carbon atoms, whose hydroxyl groups are non-terminal and vicinal. By non-terminal, such diols are designated that do not possess any hydroxyl group on a terminal carbon atom.

For the preparation of the ethylene oxide adducts, non-terminal, a, ,B-diols are utilized as the starting materials. Such diols are prepared in a known way from linear aliphatic olefins with non-terminal double bonds, for instance by epoxidation with the aid of peracids or hydrogen peroxide and lower carboxylic acids forming peracids and subsequent saponification of the epoxides. The starting materials are preferably such olefins whose double bond is about in the middle of the carbon chain. The products obtained normally are mixtures of different vicinal diols, whose diol groups are distributed statistically around a median value with the main amount in the center of the carbon chain.

The reaction of the ethylene oxide with the vicinal, non-terminal diols is carried out in a known manner in the presence of acidic or basic catalysts, preferably with the use of elevated temperatures and pressures. In the practice, preferably a two-step process is utilized. In the first step only 1 mol of ethylene oxide is reacted with 1 mol of the diol mixture. The reaction leads sub stantially to the formation of monoethoxylated diols. The reaction mixture can be purified by distilling off the unreacted diol. In the second reaction step, the monoethoxylated diol is further reacted by addition of the desired amount of ethylene oxide. By this two step reaction, preferably, each time one polyalkylene glycol chain per diol group is formed, as substantially only the primary hydroxyl groups, deriving from the first reaction step, react further with ethylene oxide with sufficient speed. The other secondary hydroxyl groups of the vicinial,non-terminal diol remain largely unchanged.

Products, suitable in the sense of the invention, are particularly the adducts of 5 to 20 mols of ethylene oxide to the named vicinal, non-terminal alkanediols having 10 to 20 carbon atoms. As starting material diols of an average alkane chain length of l4 to 16 carbons are preferred. As the tendency for foam formation rises with increasing degree of ethoxylation, for especially low-forming products the adducts from to 7 mols of ethylene oxide are preferred, when utilized without other tenside agents.

Exceptionally low-foaming products can, however, also be built with the higher ethoxylated diols by combining them with foam-suppressing substances from the group of the nonionic alkylene oxide adducts to higher alkanols, alkanediols and alkylphenols. Also the acetals from 2 mols of an alkoxylation product and 1 mol of formaldehyde are suitable as foam suppressor. The quantitative ratio by weight of the ethoxylated diols to foam suppressors amount to about 120.2 to 1:4, preferably l:O.5 to 1:2.

Preferably these low-foaming clear-rinsing agents are low-foaming rinsing compositions adapted for dishwashers consisting essentially of (A) an adduct of from 5 to 20 mols of ethylene oxide to an alkanediol having a linear alkane chain with from to carbon atoms and vicinal, non-terminal hydroxyls, and (B) an alkoxylated foam suppressing compound selected from the group consisting of(1) an alcohol having from 10 to 20 carbon atoms selected from the group consisting of a1 kanols and alkenols adducted with l to 3 mols of ethylene oxide, (2) alkylphenols having 6 to 12 carbon atoms in the alkyl adducted with l to 6 mols of ethylene oxide, (3) an alcohol selected from the group consisting of alkanols and alkanediols having from 10 to 20 carbon atoms, and alkylphenols having from 6 to 12 carbon atoms in the alkyl, adducted with from 1 to 20 mols of ethylene oxide and from 1 to 20 mols of an alkylene oxide selected from the group consisting of propylene oxide and butylene oxide wherein at least 30 mol percent of said total amount of ethylene oxide and alkylene oxide is said alkylene oxide, (4) formaldehyde acetal adducts of an alcohol selected from the group consisting of alkanols and alkanediols having from 10 to 20 carbon atoms and alkylphenols having from 6 to 12 carbon atoms in the alkyl adducted with from 10 to 30 mols of ethylene oxide, and (5) mixtures thereof, wherein the weight ratio between component A and component B is from 110.2 to 1:4.

Suitable foam suppressing compounds are, for example, ethylene oxide adducts having a low degree of ethoxylation, such as the adducts of l to 3 mols of ethylene oxide to higher fatty alcohols of a C to C chain length or to higher secondary alkanols of a C to C chain length, also the adducts of from 1 to 6 mols of ethylene oxide to alkylphenols of a C to C chain length in the alkyl. The adducts of from 1 to 3 mols of ethylene oxide to fatty alcohol mixtures of a C to C or C to C chain length, or to secondary alkanols of the average chain length of C to C as well as the adducts of 1.5 to 3 mols of ethylene oxide to nonylphenol have been proven as particularly effective.

Likewise, very well suitable as foam inhibitors are such alkylene oxide adducts in which, in the first step, 1 to 20 mols of ethylene oxide are added and in the second step 1 to 20 mols of propylene oxide and/or butylene oxide are added. The content of propylene oxide and/or butylene oxide should amount to at least 30 mol percent, preferably at least 50 mol percent, based on the total amount of the alkylene oxides adducted. Examples for such compounds are the adducts of 3 mols of ethylene oxide and 3 mols of propylene oxide or of 5 mols of ethylene oxide and 13 mols of propylene oxide to coconut fatty alcohol mixtures of a C to C chain length, the adducts of 7 mols of ethylene oxide and 5 mols of propylene oxide to a mixture of secondary aliphatic alcohols of a C to C chain length, the adduct of 5 mols of ethylene oxide and 3 mols of butylene oxide to coconut fatty alcohol mixture of a C to C chain length, the adduct of9 mols of ethylene oxide and 10 mols of propylene oxide to nonylphenol, as well as the adducts of 2 to 7 mols of ethylene oxide and 1 to 10 mols of propylene oxide, for instance 5 mols of ethylene oxide and 3 mols of propylene oxide or 5 mols of ethylene oxide and 5 mols of propylene oxide or 7 mols of ethylene oxide and 10 mols of propylene oxide to terminal or non-terminal alkanediols having an alkane of 10 to 20 carbon atoms.

Also, the formaldehyde acetals of alkylene oxide adducts have a good foam-suppressing effect. They are obtained in a known manner from 2 mols of an alkylene oxide adduct and 1 mol of formaldehyde. Preferably, 2 mols of ethylene oxide adducts having 10 to 30 ethylene oxide units adducted to the above alcohols are utilized to make acetals with 1 mol of formaldehyde. Particularly, the acetal from formaldehyde and the adduct of 20 mols of ethylene oxide to alkylphenol has been found satisfactory. This acetal can also be used in admixture for the support of the foam-inhibiting effect of the above named alkylene oxide adducts, if extremely low-foaming products are desired.

The above-named products or product combinations are sufficiently biologically degradable, if the polyglycol chain length does not surpass about 15 alkylene oxide units. In addition, the agents are very lowfoaming or practically foamless and show, over large ranges of concentration, a good draining and cleardrying effect on the various conventional kitchenware, such as porcelain plates, cutlery and particularly glasses, which are considered particularly difficult in this respect. They are, therefore, prominently suitable for the clear-rinsing of dishes after a preceding cleaning cycle, for instance with alkaline cleaners. Already in concentrations of about 0.1 gm/l a drop-free, film-like draining of the clear-rinsing liquor from the dishes is attained. A disturbing foam formation does not occur at these concentrations.

The claimed products or combinations are applied in the clear-rinsing bath in concentrations from about 0.05 to 1.0 gm/l, preferably 0.1 to 0.6 gm/l. The application concentration depends to a certain degree upon the kind of surface to be cleaned. Particularly, synthetic resin surfaces require a somewhat higher amount of clear-rinsing agents. The application is effected preferably in the form of aqueous or dilute alcoholic concentrates with contents from 10 to 60 percent by weight of the active components. As alcoholic solvent components, preferably water-miscible lower alcohols such as ethanol, propanol and isopropanol, ethylene glycol, monoethyl ether of ethylene glycol and the like, are utilized.

If the adducts themselves are liquid, they can also be applied without solvents. The concentrates are appropriately added with the aid of automatic dosing devices, as are already customary for such purposes, or manually to the clear-rinsing liquor.

The invention also involves, in the process for the mechanical washing of dishes which comprises subjecting dirty dishes to the action ofa washing solution, subjecting the washed dishes to at least one clear-rinsing solution and recovering said washed dishes, the improvement consisting of utilizing an aqueous solution containing from 0.05 to 1.0 gm per liter of an adduct of from 3 to 30 mols of ethylene oxide to an alkanediol having a linear alkane chain with from to 20 carbon atoms and vicinal, non-terminal hydroxyls, as said at least one clear rinsing solution.

If the rinsing is effected with hard water, lower organic carboxylic acids with 2 to 6 carbon atoms may be added to the concentrates or the clear-rinsing liquor for the avoidance of lime incrustations and lime hazes on the rinsed dishes. Acids are preferred that are physiologically inocuous and that possess sequestering properties toward the hardness causing salts, such as tartaric acid, lactic acid, glycolic acid and particularly citric acid. The optional addition of acid in'the clear-rinsing concentrate amounts to about 10 to 40 percent by weight.

The following specific examples are illustrative of the invention without being limitative in any manner.

EXAMPLES In a test of foaming caused by the rhythmic insertion and withdrawal of a perforated disk, the foaming behavior of various clear-rinsing agents or mixtures of them of the invention was determined. The results of the tests, given in the following tables, demonstrate the extraordinarily favorable foaming behavior of the claimed agents.

At a dosage level of 1 gm/l of clear-rinsing agents, the compounds or mixtures, listed in Table I, were stamped 20 times in a measuring cylinder with a perforated disk and subsequently the foam height in centimeters after 10, 30 and 60 seconds was recorded. Foaming heights above 20 cm are marked by x. The city water used had a dl-l (degrees German hardness) of 16. The residue of the concentrates, missing to 100 percent, is always water.

The abbreviations used in the Tables and Examples are:

E0 mols of ethylene oxide PrO mols of propylene oxide BuO mols of butylene oxide C -diol= a vicinal, non-terminal alkanediol with carbon chains with 15, 16 and 17 carbon atoms in statistical distribution, average: 16 carbon atoms.

C -diol a vicinal, non-terminal alkanediol with carbon chains with l3, l4 and carbon atoms in statistical distribution, average: 14 carbon atoms.

NP nonylphenol.

TABLE I 50C Permutit Treated Water on 7,

50C City Water 20% C -diol 5 E0 15% lsopropanol 3,3 1.6 1.4 3.2 1.9 1.8 lb

20% C diOI 5 E0 15% lsopropanol 3.5 1.5 1.2 1.3 1.0 0.8 20% Citric acid 20 20% C diol 7 E0 5.1 5.0 4.5 4.6 4.5 3.6 2b

10% C -diol 10 E0 10% C -diol 5 3 PrO 3 b 10% C -diol 10 E0 10% C -diol 5 E0] 10 PrO 10% C -diol 10 E0 10% C, -dio1+ 5 150/ 10 PrO 20% Citric acid 3d 10% C -dio1+ 10 E0 10% Coconut fatty alco- 1101, C 5 EO/ 13 PrO 3e 10% C -diol IOEO 10% Secondary C alkanol 3 E0 10% Ethanol 10% C -diol 10 E0 10% NP '1' 1.5 E0 28% Ethanol 3g 10% C diol-l0 E0 10% Unsaturated fatty alcohol mixture. C 2 E0 16%Ethanol 3h 10% C -diol 10 E0 10% NP+ 9 EO/lO Pro 10% C -diol-1' 10 E0 7% Coconut fatty alcohol C 5 EO/13 PrO 3% NP 20 E0 formaldehydde acetal 10% C -diol 15 E0 10% Secondary C alkanol 3 E 12% Ethanol 10% C -dio1 15 E0 10% NP 1.5 E0 20% Ethanol s l0C -diol 15 E0 10% Unsaturated fatty alcohol mixture,

20% Ethanol 10% C -diol 15 E0 10% NP 9 EO/lO PrO The biological degradability of the ethoxylated vicinal, non-terminal alkanediol clear-rinsing agents was measured in the closed bottle test" as biochemical oxygen requirement in percent of the theory (percent B.O.D.T.). The numerical results are summarized in the following Table 11.

By experience, a percent B.O.D .T.-value of 40 percent or more, corresponds to a good toa very good A very effective clear-rinsing agent for home dishwashing machine has the following composition:

16 percent of C -diol 5 E0 35 percent of citric acid 7 percent of ethanol 42 percent of water The clear-drying effect is very good over a concentration range offrom 0.1 to 0.7 gm/l. Also in hard water the dishes, after rinsing, dry free of spots. No disturbing foam evolution occurs.

EXAMPLE 2 A clear-rinsing agent for automatic dishwashing has the following composition:

10 percent of C -diol E0 10 percent of C -diol 7 EO/lO PrO 80 percent of water The clear-drying effect is good over a concentration range of from 0.1 to 1.0 gm/l. The foam evolution is extraordinarily low, if a liquor temperature of at least 50 C, customary in practice, is observed.

A similarly effective product, that is, however, used in hard water for the prevention oflime haze, may additionally also contain 20 percent of citric acid.

EXAMPLE 3 A clear-rinsing agent that is suitable both for home automatic dish washers and for commercial dishwashing machines, has the following composition:

10 percent of C -diol 5 E0 10 percent of C -diol 7 E0 10 percent of coconut fatty alcohol C1248 5 EO/l 3 PrO 8 percent of ethanol Remainder: water The clear-drying effect is good also on plastic dishes. The foam evolution, at a liquor temperature of at least 50 C, is very low.

For use in hard water 20 percent of citric acid may be added to this product.

EXAMPLE 4 A clear-rinsing agent for automatic dishwashing has the following composition:

10 percent of C -diol 15 E0 10 percent of NP 1.5 B0

20 percent of ethanol Remainder: water The clear-drying effect is good over a concentration range of from 0.1 to 1.0 gm/l. At liquor temperature of above 50 C, no disturbing foam occurs.

EXAMPLE 5 A clear-rinsing agent, also quite effective in hard water, has the following composition:

10 percent of C -diol 7 E0 10 percent of secondary C1145 alkanol 3 E0 20 percent of citric acid 60 percent of water The clear-drying effect is very good and the foam evolution at temperatures above 50 C is extraordinarily low.

The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, however, that other expedients known to those skilled in the art, or disclosed herein, may be employed without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. Low-foaming rinsing aqueous concentrates adapted for dishwashers consisting essentially of from 10 to 60 percent by weight of a composition consisting essentially of (A) an adduct of from 5 to 20 mols of ethylene oxide to an alkanediol having a linear alkane chain with from 10 to 20 carbon atoms and vicinal, non-terminal hydroxyls, and (B) an alkoxylated foam suppressing compound selected from the group consisting of (1) an alcohol having from 10 to 20 carbon atoms selected from the group consisting of alkanols and alkenols adducted with l to 3 mols of ethylene oxide, (2) alkylphenols having 6 to 12 carbon atoms in the alkyl adducted with l to 6 mols of ethylene oxide, (3) an alcohol selected from the group consisting of (i) alkanols having from 10 to 20 carbon atoms, (ii) alkanediols having from 10 to 20 carbon atoms, and (iii) alkylphenols having from 6 to 12 carbon atoms in the alkyl, adducted with from 1 to 20 mols of ethylene oxide plus 1 to 20 mols of an alkylene oxide selected from the group consisting of propylene oxide and butylene oxide wherein at least 30 mol percent of the total amount of ethylene oxide plus alkylene oxide is said alkylene oxide, (4) formaldehyde acetal adducts of an alcohol selected from the group consisting of alkanols and alkanediols having from 10 to 20 carbon atoms and alkylphenols having from 6 to 12 carbon atoms in the alkyl adducted with from 10 to 30 mols of ethylene oxide, and mixtures thereof, wherein the weight ratio between component A and component B is from 1: 0.2 to 1:4, from 0 to 25 percent of a water-miscible lower alcohol, and from 0 to 40 percent by weight ofa watermiscible lower organic carboxylic acid having from 2 to 6 carbon atoms and sequestering properties towards salts causing water hardness, and the remainder to 100 percent by weight, of water.

2. The aqueous concentrates of claim 1 wherein said alkanediol of component (A) has an average chain length of 14 to 16 carbon atoms.

3. The aqueous concentrates of claim 1 wherein said component (B) is an alcohol having from to 20 carbon atoms selected from the group consisting of alkanols and alkenols adducted with l to 3 mols of ethylene oxide.

4. The aqueous concentrates of claim 1 wherein said component (B) is an alkylphenol having 6 to 12 carbon atoms in the alkyl adducted with l to 6 mols of ethylene oxide.

5. The aqueous concentrates of claim 1 wherein said component (B) is component (B)(3).

6. The aqueous concentrates of claim 1 wherein said weight ratio between component A and component B is from 120.5 to 1:2.

7. In the process for the mechanical washing of dishes which comprises subjecting dirty dishes to the action of a washing solution, subjecting the washed dishes to at least one clear-rinsing solution and recovering said washed dishes, the improvement consisting of utilizing an aqueous solution containing from 0.05 to 1.0 gm per liter of an adduct of from 3 to 30 mols of ethylene oxide to an alkanediol having a linear alkane chain with from 10 to 20 carbon atoms and vicinal, non-terminal hydroxyls, as said at least one clear-rinsing solution.

8. The process of claim 7 wherein said adduct is the adduct of from 3 to 7 mols of ethylene oxide to an alkanediol having an average of from 14 to 16 carbon atoms in its linear alkane chain.

9. The process of claim 7 wherein said adduct is a mixture of adducts consisting of (A) an adduct of from 5 to 20 mols of ethylene oxide to an alkanediol having a linear alkane chain with from 10 to 20 carbon atoms and vicinal, non-terminal hydroxyls, and (B) an alkoxylated foam suppressing compound selected from the group consisting of( l an alcohol having from 10 to 20 carbon atoms selected from the group consisting of alkanols and alkenols adducted with l to 3 mols of ethylene oxide, (2) alkylphenols having 6 to 12 carbon atoms in the alkyl adducted with l to 6 mols of ethylene oxide, (3) an alcohol selected from the group consisting of (i) alkanols having from 10 to 20 carbon atoms, (ii) alkanediols having from 10 to 20 carbon atoms, and (iii) alkylphenols having from 6 to 12 carbon atoms in the alkyl, adducted with from 1 to 20 mols of ethylene oxide and from 1 to 20 mols of an alkylene oxide selected from the group consisting of propylene oxide and butylene oxide wherein at least 30 mol percent ofthe total amount of ethylene oxide plus alkylene oxide is said alkylene oxide, (4) formaldehyde acetal adducts of an alcohol selected from the group consisting of alkanols and alkanediols having from 10 to 20 carbon atoms and alkylphenols having from 6 to 12 carbon atoms in the alkyl adducted with from 10 to 30 mols of ethylene oxide, and (5) mixtures thereof, wherein the weight ratio between component A and component B is from 110.2 to 1:4.

10. The process of claim 7 wherein said adduct is present in an amount of from 0.1 to 0.6 gm per liter. 

2. The aqueous concentrates of claim 1 wherein said alkanediol of component (A) has an average chain length of 14 to 16 carbon atoms.
 3. The aqueous concentrates of claim 1 wherein said component (B) is an alcohol having from 10 to 20 carbon atoms selected from the group consisting of alkanOls and alkenols adducted with 1 to 3 mols of ethylene oxide.
 4. The aqueous concentrates of claim 1 wherein said component (B) is an alkylphenol having 6 to 12 carbon atoms in the alkyl adducted with 1 to 6 mols of ethylene oxide.
 5. The aqueous concentrates of claim 1 wherein said component (B) is component (B)(3).
 6. The aqueous concentrates of claim 1 wherein said weight ratio between component A and component B is from 1:0.5 to 1:2.
 7. In the process for the mechanical washing of dishes which comprises subjecting dirty dishes to the action of a washing solution, subjecting the washed dishes to at least one clear-rinsing solution and recovering said washed dishes, the improvement consisting of utilizing an aqueous solution containing from 0.05 to 1.0 gm per liter of an adduct of from 3 to 30 mols of ethylene oxide to an alkanediol having a linear alkane chain with from 10 to 20 carbon atoms and vicinal, non-terminal hydroxyls, as said at least one clear-rinsing solution.
 8. The process of claim 7 wherein said adduct is the adduct of from 3 to 7 mols of ethylene oxide to an alkanediol having an average of from 14 to 16 carbon atoms in its linear alkane chain.
 9. The process of claim 7 wherein said adduct is a mixture of adducts consisting of (A) an adduct of from 5 to 20 mols of ethylene oxide to an alkanediol having a linear alkane chain with from 10 to 20 carbon atoms and vicinal, non-terminal hydroxyls, and (B) an alkoxylated foam suppressing compound selected from the group consisting of (1) an alcohol having from 10 to 20 carbon atoms selected from the group consisting of alkanols and alkenols adducted with 1 to 3 mols of ethylene oxide, (2) alkylphenols having 6 to 12 carbon atoms in the alkyl adducted with 1 to 6 mols of ethylene oxide, (3) an alcohol selected from the group consisting of (i) alkanols having from 10 to 20 carbon atoms, (ii) alkanediols having from 10 to 20 carbon atoms, and (iii) alkylphenols having from 6 to 12 carbon atoms in the alkyl, adducted with from 1 to 20 mols of ethylene oxide and from 1 to 20 mols of an alkylene oxide selected from the group consisting of propylene oxide and butylene oxide wherein at least 30 mol percent of the total amount of ethylene oxide plus alkylene oxide is said alkylene oxide, (4) formaldehyde acetal adducts of an alcohol selected from the group consisting of alkanols and alkanediols having from 10 to 20 carbon atoms and alkylphenols having from 6 to 12 carbon atoms in the alkyl adducted with from 10 to 30 mols of ethylene oxide, and (5) mixtures thereof, wherein the weight ratio between component A and component B is from 1:0.2 to 1:4.
 10. The process of claim 7 wherein said adduct is present in an amount of from 0.1 to 0.6 gm per liter. 